8 papers
The crystalline cohomology of covers with a cyclic -Sylow subgroup
Jędrzej Garnek
Let be a smooth projective curve over a field with an action of a finite group . A well-known result of Chevalley and Weil describes the -module structure of cohom…
The de Rham cohomology of covers with cyclic -Sylow subgroup
Jędrzej Garnek, Aristides Kontogeorgis
Let be a smooth projective curve over a field with an action of a finite group . A well-known result of Chevalley and Weil describes the -module structure of cohom…
Indecomposable direct summands of cohomologies of curves
Jędrzej Garnek
Groups with a non-cyclic Sylow -subgroup have too many representations over a field of characteristic~ to describe them fully. A~natural question arises, whether the world of…
The "exponential" torsion of superelliptic Jacobians
Jędrzej Garnek
Let be the Jacobian of a superelliptic curve defined by the equation , where is a separable polynomial of degree non-divisible by . In this article w…
-group Galois covers of curves in characteristic II
Jędrzej Garnek
Let be an algebraically closed field of characteristic and let be a finite -group. The results of Harbater, Katz and Gabber associate a -cover of the projecti…
-group Galois covers of curves in characteristic
Jędrzej Garnek
We study cohomologies of a curve with an action of a finite -group over a field of characteristic . Assuming the existence of a certain 'magical element' in the function fiel…
Number of points of certain Artin-Schreier curves
Jędrzej Garnek
We prove a conjecture of Johansen, Helleseth and Kholosha concerning equality of exponential sums related to the cross-correlation of -sequences. In the proof we show that certa…
Equivariant splitting of the Hodge--de Rham exact sequence
Jędrzej Garnek
Let be an algebraic curve with an action of a finite group over a field . We show that if the Hodge-de Rham short exact sequence of splits -equivariantly then the…